The mail was rejected. Can the other party see it?

Take WeChat as an example, I can't see it.

When the other party refuses the message, the other party cannot see it. When a user sends a message to a WeChat friend, if the prompt message has been sent but rejected by the friend, it means that the other party has blacked out the user's micro-signal. In this case, all messages sent by the user will not be seen by the other party.